1. Field of the Invention
This invention is generally directed to tow bar assemblies for use in towing or trailering one automotive vehicle behind another and more specifically to a tow bar hitch assembly which may be normally mounted in a stored position on the front end of a trailing vehicle and yet be extended for connection to the towing or pulling vehicle. The present invention makes it possible for one person to connect the tow bar assembly between the towing and trailing vehicle without requiring the exact positioning of the vehicles relative to one another. After being connected between the two vehicles, the tow bar assembly is designed to self-center itself and the component parts thereof will automatically lock with one another in a rigid configuration for towing by slightly maneuvering the trailing or towed vehicle.
2. History of the Art
At one time or another, many people have dealt with the frustrations and hazards of utilizing conventional types and styles of tow bar hitch equipment used for connecting trailers or other vehicles to a car, truck, moving van, camper or larger recreational vehicle. When trailering relatively small boat type or equipment hauling trailers, the tow bar hitch assembly is normally fixed to the trailing or towed vehicle and conventionally takes the form of a longitudinally extending trailer tongue that is reinforced by side brace members or chains which extend outwardly to the side frame of the trailing vehicle. The towing vehicle is generally provided with a reinforced fixed hitch ball mounted thereon which is adapted to be encircled or covered by the hitch component of the tow bar assembly of the trailing vehicle with appropriate spring-loaded wedges or pins being utilized to insure a locked engagement between the ball and the trailer hitch.
In most conventional tow bar hitches, whenever it becomes necessary to align the hitch of a tow bar assembly with the ball of the towing vehicle, the entire tow bar assembly must be properly aligned with the ball so that the hitch will be properly seated therewith prior to any locking mechanisms being urged into engagement to bind the hitch with the ball element. With many prior art structures, the hitch bar or trailer tongue is fixedly mounted with respect to the tow bar assembly with the result that the entire trailing vehicle must be maneuvered simultaneously with the tow bar assembly in order to align the hitch with the ball of the towing vehicle. Even with relatively small trailers, this alignment task can present may problems and undue safety hazards. If the trailing equipment is somewhat heavy, once the equipment has begun to move, it takes a great deal of physical effort to stop such movement to assure proper alignment of the tow bar hitch with the towing vehicle. Safety risks are frequently encountered by persons who rent small trailers for use in moving personal household goods and the like on a self-help basis. Oftentimes, the weight distribution of the goods within such trailers is such as to either cause the hitch bar or tongue of the trailer to be urged upwardly or downwardly with a great deal of force about the trailer's axle. Such forces or movement must be resisted by someone trying to maneuver the trailer and such physical resistance may result in personal injury.
Other types of tow bar equipment are used in different environments where the danger of injury is lessened in that the trailing vehicle is stabilized and therefore not subject to sudden vertical movement. Such environments include the use of tow bar equipment in pulling or trailering a second vehicle such as is common practice where one person must move two vehicles between two locations or when one person wishes to tow a second vehicle behind a primary vehicle so that the secondary vehicle may be selectively used when the primary vehicle is parked in an appropriate area. In the camper and recreational vehicle industry, it is becoming more commonplace for camper and RV owners to trailer smaller family cars or jeeps and the like behind the recreational vehicle so that the smaller vehicles can be utilized when the larger vehicles are parked. This permits the recreational vehicle or camper owner to have vehicle access to areas which may be difficult to maneuver in with the larger RV or camper vehicles.
Many of the conventional tow bar structures utilized for towing one motor vehicle behind another are in the form of A-frames or T-shaped frames having a tongue or hitch bar that is fixedly oriented forwardly of the trailing vehicle. As with other prior art fixed frame tow bar devices, such structures required that the trailing vehicle be constantly manipulated forwardly, backwardly and transversely with respect to the towing vehicle in order to properly and accurately align the hitch carried by the tow bar over the receiving ball of the towing vehicle. Such an arrangement makes it practically impossible for the operator or a single person of a trailing vehicle to accurately align the hitch without receiving guidance from someone standing by to signal the operator as to the proper maneuvering of the trailing vehicle to assure proper alignment of the hitch. Due to these frustrations which are inherent in many automotive tow bar and hitch assemblies, new designs for tow bar assemblies have been proposed in an effort to increase the ease of alignment of the tow bar hitch equipment with the towing vehicle.
An early model of adjustable vehicle tow bar is disclosed in U.S. Pat. No. 2,417,871 to Heuerman. Tow bars of the type disclosed in Heuerman were originally designed to provide a straight line connection between the rear axle or a frame component of the towing vehicle and the front axle of the trailing vehicle. In Heuerman, however, such a connection was made using a pair of tubular members which were telescopingly associated with one another thereby permitting the length of the tow bar to be adjusted so as to accurately reflect the distance between the portion of the towing vehicle to which the tow bar was to be attached and the front axle of the trailing vehicle to which the tow bar was also to be attached. Locking devices were also provided to insure that the tow bar retained its adjusted position after installation. Such in-line tow bars have the distinct disadvantage of necessitating that a person utilizing the equipment access the undercarriage of both the towing and trailing vehicles in order to install the tow bar therebetween. Such an arrangement is not satisfactory for use by today's consumers. In addition, such equipment is not readily stored and therefore an extra carrying space would have to be provided for the tow bar when not in use.
In U.S. Pat. No. 3,105,706 to Adam, an adjustable tow bar hitch is disclosed which incorporates a generally T-shaped structure having an elongated trailer tongue which is pivotally mounted to the main or cross bar frame of the tow bar so as to be both slideable and pivotable with respect thereto. With such a structure, the trailer tongue may be slidingly positioned to one side of the cross bar frame and thereafter pivoted into generally parallel relationship thereto. Such an arrangement allows the tow bar to be collapsed into a compact configuration when not in use, however, the tow bar still requires that the trailing vehicle be properly aligned with the towing vehicle in order to permit the hitch portion of the tow bar to be properly aligned for coupling or seating to the connector portion or hitch ball of the towing vehicle. In use of this type of tow bar equipment, the tow bar tongue or hitch bar is initially slidingly positioned generally centrally of the cross bar frame which is attached to the trailing vehicle and thereafter the tongue pivoted into generally perpendicular relationship thereto. Although arcuate movement of the tongue is possible to align the hitch, it is necessary that the trailing vehicle be aligned so that the arcuate movement of the hitch of the tongue passes over the proper point at which the engagement between the hitch and the towing vehicle is to be made.
A more recent modification to prior art tow bar assemblies is disclosed in U.S. Pat. No. 4,577,883 to Duncan. This type of tow bar equipment is designed not only to permit the tow bar to be collapsed and stored along the front bumper of the towed or trailing vehicle when not in use but also is designed to facilitate the coupling of the hitch portion of the tow bar to the towing vehicle. The tow bar includes a main frame which is mounted to the front end of the trailing vehicle and to which a slideable sleeve is mounted so as to be both rotatably and longitudinally moved relative thereto. This arrangement permits the pivoting of the tow bar reach or tongue to be shifted both horizontally and rotated vertically relative to the main tubular cross member of the assembly. In addition, the tow bar reach or tongue is pivotally mounted to the slideable sleeve so that the reach or tongue may be oriented in a variety of directions regardless of the positioning of the slideable sleeve with respect to the main tubular cross bar of the assembly. Chains are also provided extending from the edges of the mounting frame forwardly to the front end of the tongue or trailer bar reach with the chains being relatively slack when the reach is not fully extended toward the towing vehicle. This structure enables the reach or trailer tongue to be manipulated more freely relative to the towing vehicle. As the reach of the assembly is extended, the chain allows the reach to achieve a maximum extension and thereby determines the degree of flexibility and range of coupling which is possible with the tow bar apparatus. Although such an arrangement allows greater flexibility in the movement of the coupling and hitch components, such an assembly still requires that the hitch bar or tongue be positioned close enough to the trailer hitch ball of the towing vehicle so as to permit the hitch component to be mounted thereto. Therefore, the trailing vehicle is generally manipulated so that it is in alignment with the trailer hitch ball although the connection being possible within a range to either side of the trailer hitch ball due to the limited extension which is possible of the trailer tongue. Such an arrangement, however, requires that the adjustable sleeve of the tow bar be manually manipulated when adjusting the positioning of the tow bar tongue and further requires that the adjustable sleeve be positioned centrally of the support or cross bar frame and be in a locked position prior to taking any further efforts to align the trailer hitch with the trailer hitch ball of the towing vehicle.
Some additional examples of prior art tow bar equipment include U.S. Pat. No. 3,281,163 to Wiebe and U.S. Pat. No. 4,022,489 to Shattles et al.